Forced air cooled display case



Nov. 28, 1939. "R H. TU| 2,181,635

FORCED AIR COOLED DISPLAY CASE wlTN ssEs: f INVENToR Rosca-r' H. Tum..

ATTORN Nov. '28, 1939; R, H. TULL y 2,181,635

FORCED AIR cooLED DISPLAY CASE Filed July 9,l 1938 2 sheetssheef 2F-"lG, 2.

, mvENToR Raaf-:refr H.TUL1.

ATTORNE WITNEssEs;

Patented Noir. 2s, 1939 PATENT orrlcia:`

2,181,635 FORCED Am oooLEDpisPLAY CASE Robert H.' Tull, Springfield,Mass., assignor to Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., aV corporation of Pennsylvania Application July 9,1938, Serial No. 218,270 j s claims. (o1. ca -89.5)

through the tube 23 by connecting a suitable f This invention relates torefrigerators and to a method of operating the same, and particularly torefrigerators of the type wherein the air in the refrigerated storagespace is forcibly circulated therein.

a refrigerator having two compartments, one of which may be renderedrelativelyl inactive to reduce operating expense.

Another object is to provide a method of operating a refrigerator sothat dehydration of the comestibles stored therein is inhibited.

These and other objects are effected by my invention, as will beapparent from the following description and claims taken in connectionwith the accompanying drawings forming a part of this application, whichshow a refrigerator display cabinet. The invention,however, is notlimited to this specific embodiment as it is applicable tonumerous-other types of refrigerated chambers.

In the drawings, Fig. l is a vertical section through the display caseon the line I-I of Fig. 2. Fig. 2 is a vertical section through thedisplay case on the line II-Il of Fig. 1.

Referring @w to the drawings: numeral I designates a cabinet`ofconventional construction which comprises an inner shell I I enclosingla refrigerated storage chamber 2l and an outer shell I2, between whichis located heat insulating material I3. 'The cabinet- I0 includes frontand rear walls I4 and I6 and the upper portion of the front wall I4 isinclined and contains several spaced panes of glass I5'to permit a viewof the contents of the cabinet I0; The upper portion of the rear wall I6is also inclined and is provided with sliding doors I1, the panels ofwhich are'transparent panes of glass I8. Ihe lower portion of the rearwall I6 is provided with hinged doors I9.

Located in approximately the center of the cabinet I0 is a relativelyfiat cooling unit or evaporator 22 comprising a tube 23 passing back andforth through a series of parallel and spacedapart metal strips 24 whichform fins for the tube 23. 'ine cooling unit 22 is supported on thebrackets 25. The refrigerant may be passed refrigerating apparatus (notshown) to the ends of the tube 23.

The cooling unit 22 covers substantially the entire horizontal sectionalarea of the storage chamber 2| and divides it into an upper compartment48 and a lower compartment 49. Above the cooling unit III and supportedon the brackets 26 is a grid forming a shelf 21 on which may be placeddisplay pans 28 as shown in Fig. 1. Below the cooling unit 22 is aseries of Z-shaped channels 29 which overlap one another to catch vallof the moisture dripping from the cooling unit 22, While permitting airto pass therethrough.

The cooling unit 22, the shelf 21, and the series of Z-shaped channels29 are slightly inclined from the horizontal to permit a convenient viewthrough the window I5 -of the articles of food stored on the shelf andalso to drain the moisture collected'` by the Z-shaped channels 29 intoa trough 3I located on the front -wall I4 of the cabinet I0. This trough3| drains through a tube 32 into a storage pan 33 which coverssubstantially the entire floor area ofthe cabinet I0. An

overflow drain 34 connects with this pan 33 to carry away the excesswater. The purpose of this pan 33 isv to humidify the air in the cabinetI0. The floor area of vthis pan 33 is slightly inclined and is providedwith an overflow drain 34 at its lowest point. The' entrance opening 35of this drain is' adjustableas to height so that the depth of the .waterand, therefore, the exposed surface 36 thereof is controllable byvarying the height of `the orice 35. By thus changing the exposedsurface of the water, the degree of humidity in the cabinet I0 may becontrolled. This means of controlling the humidity forms `the subjectmatter of a separate application, Serial No. 235,- 733, filed October19, 1937. The inventor and assignee are the same as in the presentapplication.

A second shelf 31 is located in the bottomof the cabinet a shortdistance above the surface of the water in the pan and forms an air duct38 between the shelf 31 and the water 36. The shelf 31 is formed ofspaced slats of`wood 39 which are supported at their edges on theinturned flanges 4I of the pan 33.

Connected with the duct 38 is an inlet conduit 42 of a blower elementcomprising a casing 43, a fan 44. and a motor 45 for driving the fan 44.The motor is driven by an electric current flowing through the wires 5Iand the controlling switch 52. The fan 44 passes the air taken from theduct 38 upwardly through a duct 46 to a horizontal duct 41 located inthe top wall of the cabinet I0. The lower surface of this horizontalduct 41 is foraminated and evenly distributes the 'air downwardlythrough the cabinet l0 Where it passes through the upper foodcompartment 48, the cooling unit 22, the spaces between the channels 29,the lower food compartment 49, and through the Spaces between the slats39, over the surface of the water 36 in the pan 33, and is thenrecirculated by the fan 44.

The cooling unit 22 is relatively flat so that the air passes quicklythrough the same and is cooled only a few degrees in temperature onpassing through. This chilling is suflicientv to abstract the heatabsorbed by the air on passing over the articles in the refrigerator andalong the walls of the refrigerator. The small degree of cooling andheating in each cycle results in but little moisture being abstracted bythe cooling unit 22 from the air, and because of its intimate contactwith the water in the pan 33 the humidity of :the yair will be high.Because of this high humidity, fruits, vegetables, meats and similarmoisture-containing foods will retain their condi- H tion and palatableappearance while stored in the refrigerator.

The large area of thecooling unit insures an even distribution oftemperature in each of the two food compartments 48 and 49. The largecontact area of the cooling unit also permits of operation at arelatively high temperature and at a corresponding high suctionpressure, thereby lowering the power consumption of the refrigerator.

The speed of the air through the display case is preferablyabout 6 feetper minute but may vary between 3 and 20 feet per minute. This low alrspeed reduces the dehydration of the comestibles in the display case.Furthermore, since but little energy is expended in the display case todrive the fan, the amount of heat which is added to the refrigeratedstorage space by the fan motor 45 is small.

'-I'he lower food compartment 49 is maintained at a lower temperaturethan the upper compartment 48 and may be utilized to carry the reservestocks of merchandise, while the upper compartment 48 may be used fordisplaying the merchandise to be sold immediately. The air in bothcompartments is, however, always maintained at temperatures above 32degrees F. 'I'he relative humidity is lower in the upper compartment 48than in the lower compartment 49, but the humidities in 'bothcompartments are fairly high. l

For overnight storage the articles of food may be removed from the uppercompartment 48 and the fan motor 45 stopped by opening the switch- 52.Most of refrigeration is then effected in the lower food compartment 49,the refrigeration occurring through convectional air currents from thecooling unit 22. This effects an appreciable saving in the operatingcost of the refrigeraton From the above it will be apparent that thisinvention provides a refrigerator in which dehydration of thecomestibles" placed therein is largely prevented. The refrigerator ofthis invention also provides a display case having two food storagechambers maintained at different temperatures for different kinds ofstorage. One of these chambers may also be rendered comparativelyinactive to reduce the operating cost of the refrigerator.

While I have shown my invention in but one s form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What I claim is:

1. A refrigerator comprising an insulated cabinetgthe length of whichexceeds its breadth, a relatively flat and substantially horizontalc001- ing unit therein dividing said refrigerator into an upper and alower refrigerated storage compartment, and motor-driven means forcirculating air through `said compartments and through said coolingunit, said motor-driven means including an air duct, an air' inlet tosaid motor-driven means extending along substantially the entire lengthof the lower compartment and an air outlet extending substantially alongth-e entire length of the upper food compartment.

2. In a refrigerator, the combination of a cabinet, a relativelyflatcooling unit therein dividing said cabinet into two storagecompartments, said coolingunit having transverse air passagessubstantially throughout its surface, said cooling unit being arrangedto cooperate with the walls of the cabinet to prevent the passage ofsubstantial quantities of airl around the cooling unit, propelling meansfor circulating air in said cabinet, means for directing air from anextended area in one compartment to said propelling means, and means fordischarging air from the propelling means into the other compartmentover an extended area and towards said cooling unit, said air thereafterpassing through the cooling unit, whereby the amount of heat removed bythe cooling unit vfrom the air passing therethrough is substantiallyuniform over the area ci' the cooling unit.

3. In a refrigerator, the combination of a cabinet, a relatively fiatand substantially horizontal cooling unit therein dividing said cabinetinto an upper and a lower storage compartment, said cooling unit havingtransverse air pas-l sages substantially throughout `its surface, saidcooling unit being arranged to cooperate with the walls of the cabinettoprevent Ithe passage of substantial quantities of air around the coolingunit, propelling means for circulating air in said cabinet, means fordirecting air from an extended area in the lower compartment to saidpropelling means, and means for discharging air from the propellingmeans into the upper compartment over an extended area and towards saidcooling unit, said air ,thereafter passing downwardly through saidcompartments and through said cooling unit, whereby 4the amount of heatremoved by the cooling unit from the air passing therethrough issubstantially uniform over the areaof the cooling unit.

4. In a refrigerator, the combination of a cabinet, a relatively at andsubstantially horizontal cooling unit therein dividing said cabinet intotwo storage compartments, said cooling unit having a. multiplicity ofclosely spaced transverse airpassages substantially throughout itssurfaces, said cooling unit being arranged to cooperate with the sidesof the cabinet to prevent the passage of substantial quantities of airaround the cooling unit, a drip collector below said cooling unit havingair passages therein, propelling means for circulating air in saidcabinet, means for directing air from an extended area in onecompartment to said propelling means, and

means for discharging air from the .propelling means into the othercompartment over an extended area and towards said cooling unit, the airthereafter passing through the cooling unit and the drip collector,whereby the air passing through the cooling unit is cooled substantiallyuniformly throughout the area thereof.

5. In a refrigerator, the combination of a cabinet, a relatively flatand substantially horizontal cooling unit therein, dividing said cabinetinto two storage compartments, said cooling unit hav` ing transverse airpassages substantially throughout its surface, said cooling unit beingarranged to cooperate with the sides of the cabinet to prevent thepassage of substantial quantities of air around the cooling unit, a panfor storing water in the lower compartment adjacent the bottom thereof,propelling means for circulating air in said cabinet, means fordirecting air adjacent said pan to said propelling means, and means fordischarging air from the propelling means into the other compartmentover an extended area and towards said cooling unit, the air thereafterpassing through the cooling unit, whereby the air passing therethroughis cooled substantially uniformly throughout the area of the coolingunit.

6. In a refrigerator, the combination of a cabinet, a relatively at andsubstantially horizontal cooling unit therein dividing said cabinet intotwo storageA compartments, said cooling unit having transverse airpassages substantially throughout its surface, said cooling unit beingarranged to cooperate with the walls of the cabinet to prevent thepassage of substantial quantities of air around the cooling unit, a dripcollector below said cooling unit comprising overlapping troughs, saidtroughs being spaced apart to provide air passages, a pan for storingwater in the lower compartment adjacent the bottom thereof, means forconducting moisture collected by said dri-p collector to the pan,propelling means for circulating air in said cabinet, means fordirecting air from an extended area adjacent said water pan into saidpropelling means, means for discharging air from the propelling meansinto the other compartment over an extended area and towards saidcooling unit, the air thereafter passing through the cooling unit anddrip collector, whereby the air passing through the cooling unit iscooled substantially uniformly throughout the area thereof.

7. In a refrigerator, the combination of a cabinet, a relatively flatand substantially horizontal cooling unit therein dividing said cabinetinto upper and lower food storage compartments, said cooling unit havingtransverse air passages substantially throughout its surface, saidcooling unit being arranged to cooperate with the walls of the cabinetto prevent the passage of substantial quantities of air around thecooling unit, propelling means for circulating air in said cabinet,means for directing air from an extended area in one compartment intosaid propelling means and means for discharging air from the propellingmeans into the other compartment over an extended area and towards saidcooling unit, the

and means for rendering said air propelling means inactive to reduce therefrigerationof said upper` compartment.

8. A refrigerator comprising a cabinet, a relatively flat cooling unithaving a multiplicity of closely spaced transverse air passagestherethrough and throughout substantially its entire area, said coolingunit being disposed in said cabinet to divide the same into two foodstorage chambers and to occupy more than half of the cross-sectionalarea of said cabinet in the plane of the cooling unit, air propellingmeans and ducts -associated with the cabinet to pass air through onecompartment, then transversely through the cooling unit andsubstantially uniformy throughout its area, and then through the othercompartment, said transverse movement of the air through the coolingunit being at a velocity below twenty feet per minute and providingsubstantially the sole contact of the air therewith, whereby saidpassage of the air at said velocity through the compartments eiectssubstantially a uniform temperature in each of said compartments and alow and uniform moisture abstraction from the air throughout saidcooling unit.

ROBERT H. TULL.

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